Enhancing surgical performance in cardiothoracic surgery with innovations from computer vision and artificial intelligence: a narrative review.

When technical requirements are high, and patient outcomes are critical, opportunities for monitoring and improving surgical skills via objective motion analysis feedback may be particularly beneficial. This narrative review synthesises work on technical and non-technical surgical skills, collaborative task performance, and pose estimation to illustrate new opportunities to advance cardiothoracic surgical performance with innovations from computer vision and artificial intelligence. These technological innovations are critically evaluated in terms of the benefits they could offer the cardiothoracic surgical community, and any barriers to the uptake of the technology are elaborated upon. Like some other specialities, cardiothoracic surgery has relatively few opportunities to benefit from tools with data capture technology embedded within them (as is possible with robotic-assisted laparoscopic surgery, for example). In such cases, pose estimation techniques that allow for movement tracking across a conventional operating field without using specialist equipment or markers offer considerable potential. With video data from either simulated or real surgical procedures, these tools can (1) provide insight into the development of expertise and surgical performance over a surgeon's career, (2) provide feedback to trainee surgeons regarding areas for improvement, (3) provide the opportunity to investigate what aspects of skill may be linked to patient outcomes which can (4) inform the aspects of surgical skill which should be focused on within training or mentoring programmes. Classifier or assessment algorithms that use artificial intelligence to 'learn' what expertise is from expert surgical evaluators could further assist educators in determining if trainees meet competency thresholds. With collaborative efforts between surgical teams, medical institutions, computer scientists and researchers to ensure this technology is developed with usability and ethics in mind, the developed feedback tools could improve cardiothoracic surgical practice in a data-driven way.

Beyond the usual suspects: Reviewing infections caused by typically-commensal Neisseria species.

OBJECTIVE: Few data outside of individual case reports are available on non-meningococcal, non-gonococcal species of Neisseria as causative agents of invasive disease. This review collates disease, organism and patient information from case reports on the topic. METHODS: A literature search was performed examining articles describing diseases caused by non-meningococcal and non-gonococcal Neisseria. FINDINGS: Neisseria present as opportunistic pathogens causing a wide variety of diseases including serious presentations, endocarditis being the most common condition described and N. mucosa the most commonly presenting pathogen overall. Disease may occur in otherwise healthy patients, although risk factors for infection include recent surgery, an immunocompromised state, poor oral health, and intravenous drug use. CONCLUSIONS: Commensal Neisseria infections are rare but can present serious invasive diseases. Further research is required to determine why some species cause disease more than others or why some are inclined towards particular manifestations.

Demographics and deprivation in obstetric brachial plexus palsy: a retrospective cohort study.

The present study analyses the relationships between deprivation and obstetric brachial plexus palsy (OBPP). A retrospective observational study was conducted of infants with OBPP seen between 2008 and 2020 (n = 321). The index of multiple deprivation (IMD) was used to assign an IMD rank to patients based on birth postcode and the relationship with OBPP was analysed, including deprivation, gestational diabetes, age at referral and at first assessment. Quintile-based analysis demonstrated over-representation of patients from more deprived neighbourhoods (n = 109, 39%) living in the top 20% most deprived neighbourhoods. A total of 48 (15%) mothers had diabetes and 98 (31%) infants underwent surgical brachial plexus exploration (a marker of disease severity). Neither diabetes, age at referral nor age at first assessment were associated with IMD score. This suggests that neighbourhood deprivation is associated with OBPP, though the mechanisms are unclear. Further studies in this area may enable targeted health intervention for more deprived maternal and infant groups.Level of evidence: III.

Early experience of a new national lung allocation scheme in the UK based on clinical urgency.

INTRODUCTION: A new UK Lung Allocation Scheme (UKLAS) was introduced in 2017, replacing the previous geographic allocation system. Patients are prioritised according to predefined clinical criteria into a three-tier system: the super-urgent lung allocation scheme (SULAS), the urgent lung allocation scheme (ULAS) and the non-urgent lung allocation scheme (NULAS). This study assessed the early impact of this scheme on waiting-list and post-transplant outcomes. METHODS: A cohort study of adult lung transplant registrations between March 2015 and November 2016 (era-1) and between May 2017 and January 2019 (era-2). Outcomes from registration were compared between eras and stratified by urgency tier and diagnostic group. RESULTS: During era-1, 461 patients were registered. In era-2, 471 patients were registered (19 (4.0%) SULAS, 82 (17.4%) ULAS and 370 (78.6%) NULAS). SULAS patients were younger (median age 35 vs 50 and 55 for urgent and non-urgent, respectively, p=0.0015) and predominantly suffered from cystic fibrosis (53%) or pulmonary fibrosis (37%). Between eras 1 and 2, the odds of transplantation within 6 months of registration were increased (OR=1.41, 95% CI 1.07 to 1.85, p=0.0142) despite only a 5% increase in transplant activity. Median time-to-transplantation during era-1 was 427 days compared with waiting times in era-2 of 8 days for SULAS, 15 days for ULAS and 585 days for NULAS patients. Waiting-list mortality (15% era-1 vs 13% era-2; p=0.5441) and post-transplant survival at 1 year (81.3% era-1 vs 83.3% era-2; p=0.6065) were similar between eras. CONCLUSION: The UKLAS scheme prioritises the critically ill and improves transplantation odds. The true impact on waiting-list mortality and post-transplant survival requires further follow-up.

A distractions capture tool for cardiac surgery and lung transplantation: impact on outcomes.

OBJECTIVES: Surgical distractions are associated with worse patient outcomes. Lung transplantation and cardiac surgery's multi-disciplinary nature, and their inherent complexities render them more vulnerable to distractions. We aim to use a novel distractions capture tool to evaluate the severity of distractions during cardiac surgery (CS) and lung transplantation (LTx) and assess its impact on post-operative complications. METHODS: A prospective 'blinded' study was undertaken by direct observation of distractions during CS and LTx. Events were identified using the Imperial College Error Capture tool (ICECAP). Number and severity of distractions were correlated with post-operative outcomes (ICU & hospital stay, bleeding and anastomotic complications). RESULTS: In LTx, we observed 2059 distractions within 287 h across 41 surgeries. In CS, we observed 1089 distractions within 192 h across 62 surgeries. Surgeons were consciously aware of 19.2% (LTx) and 21.3% (CS) of recorded events. Distractions consisted of procedure-independent pressures (61% LTx vs 56% CS), equipment problems (15% LTx vs 23%CS), communication (12% LTx vs 12% CS), technical problems or patient safety concerns (12% LTx vs 9% CS). In CS, 91% of procedure-independent pressures were non-operative distractions whilst LTx recorded 83%. Staff absences at a critical moment of surgery were recorded at 9% (LTx) and 7% (CS). The number and severity of distractions correlated with bleeding (CS p < 0.001, LTx p < 0.01), prolonged ICU stay (CS p = 0.002, LTx p = 0.002), hospital stay (CS p < 0.001) and anastomotic complications(LTx p < 0.03). CONCLUSIONS: ICECAP as a novel surgical distractions capture tool was effective & applicable to both elective cardiac and urgent transplant surgeries. Surgeons were unaware of a large number of distractions & interruptions. Distractions were associated with longer ICU stay and higher rate of bleeding.

Chemotherapy supply chain management, safe-handling and disposal in Ethiopia: the case of Tikur Anbessa specialized hospital.

Optimal chemotherapy management is substandard in low and middle-income countries. We aimed to identify major gaps to design interventional strategies for improved chemotherapy management at Tikur Anbessa Specialized Hospital (TASH), Ethiopia. This study was conducted using an observational checklist, open-ended questions, record review, and key informant interviews of department heads and focal persons at TASH. Findings were categorized into specific themes that developed. Chemotherapy represented 60.2% of the hospital medication budget. Drug utilization was quantified via monthly consumption documentation and forecasting. However, unreliable data resulted in frequent stockouts (unavailability of the item when it is needed) of chemotherapy with only 67.8% availability. Thirteen healthcare personnel (9 nurses, 2 pharmacists and 2 hospital cleaners) were interviewed: all clinical staff but neither of hospital cleaners believed that they were at risk of hazardous agents. Challenges identified included inadequate and frequent stockouts (unavailability of the item when it is needed) of personal protective equipment, lack of standardized guidelines for chemotherapy handling, admixture, and disposal, lack of designated preparation rooms, and lack of training. All nine nurses handled chemotherapy admixtures despite only two nurses previously receiving in-service training. Most of the participants had never witnessed the disposal of anticancer drugs. Prompted by the results of this study, a dialogue was initiated among members of TASH, the American Cancer Society and the University of North Carolina to implement action-oriented projects to address the gaps identified at TASH. These gaps directly and indirectly affect care and treatment outcomes of patients at a large cancer center. Collaborations with well-resourced centers are potential models for improving chemotherapy management.

Processes and perceptions of chemotherapy supply chain in Ethiopia: A mixed-method study.

BACKGROUND: The impact and downstream effects of the chemotherapy supply chain in Ethiopia are not well understood. The purpose of this study was to identify perceived gaps in supply chain and characterize their impact on patient care. METHODS: A concurrent mixed-method study was conducted at a large academic cancer center in Ethiopia. In-depth interviews (IDIs) and surveys were completed in collaboration with external stakeholders with knowledge about chemotherapy supply chain in Ethiopia. Thematic coding was used for qualitative analysis of IDI and descriptive statistics were used to summarize quantitative survey data. RESULTS: Six stakeholders participated in the IDIs and seven completed surveys. IDIs revealed that most chemotherapeutic agents are purchased by the Ethiopian Pharmaceutical Supply Agency (EPSA) and are distributed to cancer treatment centers. A free-market purchasing option also exists, but for chemotherapy obtained outside of government-subsidized channels, the potential for substandard or falsified chemotherapy was a concern. Participants expressed confidence that the correct treatment was administered to patients, but viewpoints on reliability and consistency of medication supply were variable. Quantitative data from the survey showed that participants were not confident that medications are prepared safely and correctly. Improper storage and manipulation of high-risk medications remain a significant risk to staff. CONCLUSIONS: This study provides insight from a healthcare staff perspective on how gaps in the chemotherapy supply chain process impact patient care in a low-income country. Inventory management, disruptions in supply chain, and product integrity were perceived as the largest gaps in the current chemotherapy supply chain structure.

Do older surgeons have safer hands? A retrospective cohort study.

BACKGROUND: For complex surgical procedures a volume-outcome relationship can often be demonstrated implicating multiple factors at a unit and surgeon specific level. This study aims to investigate this phenomenon in lung transplantation over a 30-year period with particular reference to surgeon age and experience, cumulative unit activity and time/day of transplant. METHODS: Prospective databases identified adult patients undergoing isolated lung transplantation at a single UK centre between June 1987 and October 2017. Mortality data was acquired from NHS Spine. Individual surgeon demographics were obtained from the General Medical Council. Student t-test, Pearson's Chi-squared, Logistic Regression, and Kaplan-Meier Survival analyses were performed using Analyse-it package for MicrosoftExcel and STATA/IC. RESULTS: 954 transplants (55.9% male, age 44.4 ± 13.8 years, 67.9% bilateral lung) were performed, with a median survival to follow-up of 4.37 years. There was no difference in survival by recipient gender (p = 0.661), between individual surgeons (p = 0.224), or between weekday/weekend procedures (p = 0.327). Increasing centre experience with lung transplantation (OR1.001, 95%CI: 1.000-1.001, p = 0.03) and successive calendar years (OR1.028, 95%CI: 1.005-1.052, p = 0.017) was associated with improved 5-year survival. Advancing surgeon age at the time of transplant (mean, 48.8 ± 6.6 years) was associated with improved 30-day survival (OR1.062, 95%CI: 1.019 to1.106, p = 0.003), which persisted 5 years post-transplant (OR1.043, 95%CI: 1.014-1.073, p = 0.003). Individual surgeon experience, measured by the number of previous lung transplants performed, showed a trend towards improved outcomes at 30 days (p = 0.0413) with no difference in 5-year survival (p = 0.192). CONCLUSIONS: Our study demonstrates a relationship between unit volume, increasing surgeon age and survival after lung transplantation. A transplant volume: outcome relationship was not seen for individual surgeons.

Diagnosis and predicted outcomes of patients with cystic fibrosis related liver disease considered for lung transplantation.

INTRODUCTION: There is no gold standard criterion for the diagnosis of cystic fibrosis-related liver disease (CFRLD) and there is uncertainty over its impact on the outcome of lung transplantation. METHOD: Lung recipients (n = 238) were divided into two groups-CFRLD and non-CFRLD based on a modified aspartate aminotransferase-to-platelet ratio index (APRI) score (mAPRI) to diagnose CFRLD and predict severity of liver disease. Groups were compared to assess validity of the diagnosis and survival outcomes. RESULT: The new diagnostic criterion was effective at differentiating CFRLD from non-CFRLD. There was no significant difference in the survival between two groups at short, medium, or long term demonstrated by the Kaplan-Meier plot with survival of 85%, 73%, 47%, 18.6%, and 4.7% at 1, 2, 5, 10, and 15 years respectively. A mAPRI score of greater than .2 had a sensitivity of 43.0% but a specificity of 82.5 % for diagnosis of CFRLD and 46.5% sensitivity but 100% specificity in predicting an ultrasound/biopsy proven hepatic abnormality associated with CFRLD. CONCLUSION: A mAPRI sore is a highly specific non-invasive tool for diagnosis of CFRLD. Recipients with CFRLD but grossly preserved hepatocellular function have a similar outcome to patients without CFRLD.

Transcatheter Device Therapy and the Integration of Advanced Imaging in Congenital Heart Disease.

Transcatheter device intervention is now offered as first line therapy for many congenital heart defects (CHD) which were traditionally treated with cardiac surgery. While off-label use of devices is common and appropriate, a growing number of devices are now specifically designed and approved for use in CHD. Advanced imaging is now an integral part of interventional procedures including pre-procedure planning, intra-procedural guidance, and post-procedure monitoring. There is robust societal and industrial support for research and development of CHD-specific devices, and the regulatory framework at the national and international level is patient friendly. It is against this backdrop that we review transcatheter implantable devices for CHD, the role and integration of advanced imaging, and explore the current regulatory framework for device approval.

Phase I Study of High-Dose L-methylfolate in Combination with Temozolomide and Bevacizumab in Recurrent IDH wild-type High-Grade Glioma.

Purpose: IDH mutations in low-grade gliomas (LGGs) results in improved survival and DNA hypermethylation compared to IDH wild-type LGGs. IDH-mutant LGGs become hypomethylated during progression. It's uncertain if methylation changes occur during IDH wild-type GBM progression and if the methylome can be reprogrammed. This phase I study evaluated the safety, tolerability, efficacy and methylome changes after L-methylfolate (LMF) treatment, in combination with temozolomide and bevacizumab in patients with recurrent high-grade glioma. Patients and Methods: Fourteen patients total, 13 with GBM, one with anaplastic astrocytoma, all IDH wild-type were enrolled in the study. All patients received LMF at either 15, 30, 60, or 90 mg daily plus temozolomide (75mg/m2 5 days per month) and bevacizumab (10mg/kg every two weeks). Results: No MTD was identified. LMF treated had mOS of 9.5 months (95% CI, 9.1-35.4) comparable to bevacizumab historical control 8.6 months (95% CI, 6.8-10.8). Six patients treated with LMF survived more than 650 days. Across all treatment doses the most adverse events were diarrhea (7%, 1 patient, grade 2), reflux (7%, 1 patient, grade 2), and dysgeusia (7%, 1 patient, grade 2). In the six brains donated at death, there was a 25% increase in DNA methylated CpGs compared to the paired initial tumor. Conclusions: LMF in combination with temozolomide and bevacizumab was well tolerated in patients with recurrent IDH wild-type high-grade glioma. This small study did not establish a superior efficacy with addition of LMF compared to standard bevacizumab therapy, however, this study did show methylome reprogramming in high-grade glioma.

Effect of Incidental Findings Information on Lung Cancer Screening Intent: a Randomized Controlled Trial.

BACKGROUND: The Centers for Medicare & Medicaid Services requires decision aid use for lung cancer screening (LCS) shared decision-making. However, it does not require information about incidental findings, a potential harm of screening. OBJECTIVE: To assess the effect of incidental findings information in an LCS decision aid on screening intent as well as knowledge and valuing of screening benefits and harms. DESIGN: Randomized controlled trial conducted online between July 16, 2020, and August 22, 2020. PARTICIPANTS: Adults 55-80 years, eligible for LCS. INTERVENTION: LCS video decision aid including information on incidental findings or a control video decision aid. MAIN MEASURES: Intent to undergo LCS; knowledge regarding the benefit and harms of LCS using six knowledge questions; and valuing of six benefits and harms using rating (1-5 scale, 5 most important) and ranking (ranked 1-6) exercises. KEY RESULTS: Of 427 eligible individuals approached, 348 (83.1%) completed the study (173 intervention, 175 control). Mean age was 64.5 years, 48.6% were male, 73.0% white, 76.3% with less than a college degree, and 64.1% with income < $50,000. There was no difference between the intervention and controls in percentage intending to pursue screening (70/173, 40.5% vs 73/175, 41.7%, diff 1.2%, 95% CI - 9.1 to 11.5%, p = 0.81). Intervention participants had a higher percentage of correct answers for the incidental findings knowledge than controls (164/173, 94.8% vs 129/175, 73.7%, 95% CI - 28.4 to - 13.8%, p < 0.01). Incidental findings had the fifth highest mean importance rating (4.0 ± 1.1) and the third highest mean ranking (3.6 ± 1.5). There was no difference in mean rating or ranking of incidental findings between intervention and control groups (rating 4.0 vs 3.9, diff 0.1, 95% CI - 0.2, 0.3, p = 0.51; ranking 3.6 vs 3.6, diff 0.02, 95% CI - 0.3, 0.3, p = 0.89). CONCLUSIONS: Incidental findings information in a LCS decision aid did not affect LCS intent, but it resulted in more informed individuals regarding these findings. In formulating screening preferences, incidental findings were less important than other benefits and harms. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04432753.

Prospective biomarker study in newly diagnosed glioblastoma: Cyto-C clinical trial.

BACKGROUND: Glioblastoma (GBM) has a 5-year survival rate of 3%-5%. GBM treatment includes maximal resection followed by radiotherapy with concomitant and adjuvant temozolomide (TMZ). Cytochrome C oxidase (CcO) is a mitochondrial enzyme involved in the mechanism of resistance to TMZ. In a prior retrospective trial, CcO activity in GBMs inversely correlated with clinical outcome. The current Cyto-C study was designed to prospectively evaluate and validate the prognostic value of tumor CcO activity in patients with newly diagnosed primary GBM, and compared to the known prognostic value of MGMT promoter methylation status. METHODS: This multi-institutional, blinded, prospective biomarker study enrolled 152 patients with newly diagnosed GBM who were to undergo surgical resection and would be candidates for standard of care. The primary end point was overall survival (OS) time, and the secondary end point was progression-free survival (PFS) time. Tumor CcO activity and MGMT promoter methylation status were assayed in a centralized laboratory. RESULTS: OS and PFS did not differ by high or low tumor CcO activity, and the prognostic validity of MGMT promoter methylation was confirmed. Notably, a planned exploratory analysis suggested that the combination of low CcO activity and MGMT promoter methylation in tumors may be predictive of long-term survival. CONCLUSIONS: Tumor CcO activity alone was not confirmed as a prognostic marker in GBM patients. However, the combination of low CcO activity and methylated MGMT promoter may reveal a subgroup of GBM patients with improved long-term survival that warrants further evaluation. Our work also demonstrates the importance of performing large, multi-institutional, prospective studies to validate biomarkers. We also discuss lessons learned in assembling such studies.

Impact of postoperative dexamethasone on survival, steroid dependency, and infections in newly diagnosed glioblastoma patients.

BACKGROUND: We examined the effect of dexamethasone prescribed in the initial 3 postoperative weeks on survival, steroid dependency, and infection in glioblastoma patients. METHODS: In this single-center retrospective cohort analysis, we electronically retrieved inpatient administration and outpatient prescriptions of dexamethasone and laboratory values from the medical record of 360 glioblastoma patients. We correlated total dexamethasone prescribed from postoperative day (POD) 0 to 21 with survival, dexamethasone prescription from POD30 to POD90, and diagnosis of an infection by POD90. These analyses were adjusted for age, Karnofsky performance status score, tumor volume, extent of resection, IDH1/2 tumor mutation, tumor MGMT promoter methylation, temozolomide and radiotherapy initiation, and maximum blood glucose level. RESULTS: Patients were prescribed a median of 159 mg [109-190] of dexamethasone cumulatively by POD21. Every 16-mg increment (4 mg every 6 hours/day) of total dexamethasone associated with a 4% increase in mortality (95% confidence interval [CI] 1%-7%, P < .01), 12% increase in the odds of being prescribed dexamethasone from POD30 to POD90 (95% CI 6%-19%, P < .01), and 10% increase in the odds of being diagnosed with an infection (95% CI, 4%-17%, P < .01). Of the 175 patients who had their absolute lymphocyte count measured in the preoperative week, 80 (45.7%) had a value indicative of lymphopenia. In the POD1-POD28 period, this proportion was 82/167 (49.1%). CONCLUSIONS: Lower survival, steroid dependency, and higher infection rate in glioblastoma patients associated with higher dexamethasone administration in the initial 3 postoperative weeks. Nearly half of the glioblastoma patients are lymphopenic preoperatively and up to 1 month postoperatively.

What is the effect of a decision aid on knowledge, values and preferences for lung cancer screening? An online pre-post study.

OBJECTIVE: To examine if a decision aid improves knowledge of lung cancer screening benefits and harms and which benefits and harms are most valued. DESIGN: Pre-post study. SETTING: Online. PARTICIPANTS: 219 current or former (quit within the previous 15 years) smokers ages 55-80 with at least 30 pack-years of smoking. INTERVENTION: Lung cancer screening video decision aid. MAIN MEASURES: Screening knowledge tested by 10 pre-post questions and value of benefits and harms (reducing chance of death from lung cancer, risk of being diagnosed, false positives, biopsies, complications of biopsies and out-of-pocket costs) assessed through rating (1-5 scale) and ranking (top three ranked). RESULTS: Mean age was 64.7±6.1, 42.5% were male, 75.4% white, 48.4% married, 28.9% with less than a college degree and 67.6% with income

Serum Proteomics and Plasma Fibulin-3 in Differentiation of Mesothelioma From Asbestos-Exposed Controls and Patients With Other Pleural Diseases.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is difficult to diagnose. An accurate blood biomarker could prompt specialist referral or be deployed in future screening. In earlier retrospective studies, SOMAscan proteomics (Somalogic, Boulder, CO) and fibulin-3 seemed highly accurate, but SOMAscan has not been validated prospectively and subsequent fibulin-3 data have been contradictory. METHODS: A multicenter prospective observational study was performed in 22 centers, generating a large intention-to-diagnose cohort. Blood sampling, processing, and diagnostic assessment were standardized, including a 1-year follow-up. Plasma fibulin-3 was measured using two enzyme-linked immunosorbent assays (CloudClone [used in previous studies] and BosterBio, Pleasanton, CA). Serum proteomics was measured using the SOMAscan assay. Diagnostic performance (sensitivity at 95% specificity, area under the curve [AUC]) was benchmarked against serum mesothelin (Mesomark, Fujirebio Diagnostics, Malvern, PA). Biomarkers were correlated against primary tumor volume, inflammatory markers, and asbestos exposure. RESULTS: A total of 638 patients with suspected pleural malignancy (SPM) and 110 asbestos-exposed controls (AECs) were recruited. SOMAscan reliably differentiated MPM from AECs (75% sensitivity, 88.2% specificity, validation cohort AUC 0.855) but was not useful in patients with differentiating non-MPM SPM. Fibulin-3 (by BosterBio after failed CloudClone validation) revealed 7.4% and 11.9% sensitivity at 95% specificity in MPM versus non-MPM SPM and AECs, respectively (associated AUCs 0.611 [0.557-0.664], p = 0.0015) and 0.516 [0.443-0.589], p = 0.671), both inferior to mesothelin. SOMAscan proteins correlated with inflammatory markers but not with asbestos exposure. Neither biomarker correlated with tumor volume. CONCLUSIONS: SOMAscan may prove useful as a future screening test for MPM in asbestos-exposed persons. Neither fibulin-3 nor SOMAscan should be used for diagnosis or pathway stratification.

Toxicity of Refugio Beach Oil to Sand Crabs (Emerita analoga), Blue Mussels (Mytilus sp.), and Inland Silversides (Menidia beryllina).

Monterey formation crude oil spilled from an onshore pipeline and entered the surf zone near Refugio State Beach, Santa Barbara County, California (USA) on 19 May 2015. During this season, early life stages of many marine fish and invertebrates were present. Surf zone water and beach porewater samples were collected during the 4 mo after the spill and 2 yr later for chemical analyses. Elevated polycyclic aromatic hydrocarbon (PAH) and total petroleum hydrocarbon concentrations were observed in surf zone water and porewater near the release point, declining with distance and time. Early life stage toxicity was investigated by conducting 6- and 7-d static renewal bioassays with sand crab (Emerita analoga) post larvae (megalopae) and inland silverside larvae (Menidia beryllina), respectively, and a 48-h blue mussel (Mytilus sp.) embryo development bioassay. Dilutions of a high-energy water accommodated fraction of the Refugio Beach oil and a seawater control were prepared to simulate surf zone PAH concentrations (nominal PAH45 ; 0, 0.5, 1, 5, 10, 50, 100, and 500 µg/L). The PAH45 median lethal concentrations (LC50s), based on measured concentrations, were 381 µg/L for Mytilus sp., 75.6 µg/L for Menidia, and 40.9 µg/L for Emerita. Our results suggest that PAH concentrations in coastal waters of the spill-affected area were potentially lethal to early life stages of fish and invertebrates. Environ Toxicol Chem 2021;40:2578-2586. © 2021 SETAC.

Just 2% of SARS-CoV-2-positive individuals carry 90% of the virus circulating in communities.

We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral "supercarriers" and possibly also superspreaders.